Drag and drop into your minecraft.jar the files for your minecraft version

Drag and drop the content of the “tp” folder into your favorite texturepack and turn custom colors on optifine settings

You are now able to use one of the “original” presets : go into the “shader” folder then into the “original” folder and choose a performance preset. Open the folder corresponding to the performance preset you choose, open this “shaders” folder and drag and drop all the .fsh and .vsh files into your minecraft.jar/shaders.

To change shaders simply replace the content of the shaders folder for another shader preset.